On-grid domestic battery storage

Martyn1981 wrote: »

Kinda circular thinking, with gains and losses cancelling out. Like I said, made me chuckle, trying to overthink again.

I went through exactly the same cycle, thought about swapping out the immersion for a 1kw one, installing an additional element etc but most of it was down to the way Id set up the batteries initially. Two pylontechs didnt supply enough for the immersion if the sun went in so it ended up switching to mains. Four did supply enough so that was part of the reason for the upgrade, to allow full 16A draw (or thereabouts with losses).


I dont have the hive like Nick but have just a push button stop start with variable timer on my immersion. With experimentation 15 mins is enough to get me enough hot water for the power shower. So as long as I push the button 15 mins before I need a shower it is grand!

The 1kw element would have pushed that time out considerably and 15 minutes is almost on demand..

A hive like solution is on the to-do list but pushing a button after Ive made my morning coffee is the simplest easiest solution... ...until the morning you forget that is...


At this time of year Im finding I have at least 60% of the battery first thing in the morning, hence the reason for going for the ASHP to do the nighttime heating and Im using about 20-30% of the battery now to just run it. Temperature dropped here last night significantly so had to go back to the oil for a half hour. It was also a dull(ish) day here yesterday so the battery will never replace the fossil fuel side but it sure is taking a load off! Discounting time away from home that was 11 days without using the oil at all, everything from the sun and only I think 12kwh imported since first of April.



Im not familiar with the Hive but that type of solution where you can utilise battery capacity balanced with your excess export to feed other parts of your energy usage during the day is definitely the way to go. If ROI really matters to your calculations then its the best way to maximise that, certainly in terms of making the system work for you. Of course all the lifetime and lifecycle calculations are just imponderables for most of this kit at the minute. They can publish figures all they like but it really does depend on your usage.
Ive just removed the clutch master cylinder from my old Alfa 156, it failed after 75k miles, or in real terms 19 years and 2 days. I suspect it wasnt the 75k miles that made it fail judging by the internal seals, just old age. The replacement will have a 5 year warranty but thats just based on average usage and miles and and and including being used most days, the clutch slave cylinder failed after I hadnt used it in a year as it needed regular movement to provide lubrication. I keep that in mind when occasionally using the boiler during the summer, last thing I want to do is turn on again in October to find out it doesnt!


The wear and tear on the battery is going to be the interesting bit going forward, watching the battery management is also interesting, they do seem to be doing some clever stuff moving charge around the four units. I havent been monitoring it long enough to work out the cycles as it doesnt take charge from batteries uniformly unless theres a big load and it does seem to switch the battery that it takes the low energy charge from periodically. When I get a full summers usage out of it I can have a look to see if certain batteries are favoured (or if I have a dud one, or mismatch of some sort) and then monitor that going forward.

Another project....

I've tidied up the EPS adding a 2 gang socket & an emergency bulkhead light.



I then moved onto the incoming supply & fitted a generator switch. This breaks the grid connection before making the generator connection.





The completed job...



In EPS mode...

1961Nick wrote: »

This evening I replaced the Hive control with a wifi fused spur ....

I had not realised there was such a thing but I found one made by Timeguard being sold for around £40. Is that what you used?

Martyn1981 wrote: »

OK this is weird, take the picture from the Chicago article, then change the colour of the battery from black to white, and what do you get:

Anesco launches domestic solar-plus-storage offering

Just a placeholder image credited to Sonnen and they dont mention Sonnen in the article. Naughty.
The rest is cut and paste from a press release.


Im in Chicago at the end of next month, might give them a shout and call past if I have time.